Semi-continuous approach for the modeling of thin woven composite panels applied to oblique impacts on helicopter blades

In aeronautics, passenger safety and reliability of structures are essential aspects. In the specific case of helicopters, blades are subjected to impact loadings. Modeling these phenomena continue to be difficult and experimental tests often replace the prediction. The following work will focus on the experimental and numerical study of an oblique impact on the skin of the blade. It is equivalent in a first approach to an impact on a sandwich panel made up of a foam core and a thin woven composite skin. The objectives are to identify the mechanisms of damage in the skin for this kind of loading and to develop a representative modeling of the chronology of damage adapted to the modeling of the complete structure. Thus, a semi-continuous F.E. explicit modeling has been developed. It relies on the development of a specific damageable element at the bundles scale. Satisfactory numerical results are obtained. They allow the identification of the damage mechanism of the woven skin.